<svg xmlns="http://www.w3.org/2000/svg">
  <style>
    @font-face {
      font-family: "Liberation";
      src: url(resources/svg.woff);
    }
  </style>
  <mask id="m" x="0" y="0" width="200" height="200">
    <rect x="30" y="60" width="80" height="80" stroke-width="5"
      stroke="black" fill="red"/>
    <rect x="30" y="50" width="10" height="10" stroke="none"
      fill="turquoise" />
  </mask>
  <rect width="200" height="200" mask="url(#m)"/>
</svg>
